The present invention relates to an EMI protective spring plate for motherboard and, more particularly, to such an EMI protective spring plate, which has a lower dead point design that prevents permanent deformation.
In order to protect a motherboard against EMI (electromagnetic interference), spring plates may be installed in the border of the motherboard to support a plate shield. FIGS. From 1 through 3 show a spring plate constructed according to the prior art for this purpose. This structure of spring plate 10a comprises a flat top contact portion 11a, which supports a shielding cover plate 40a, a flat bottom soldering portion 15a, which is soldered to the motherboard 30a with tin soldering paste 20a, two side plate portions 14 vertically downwardly extended from two ends of the flat top contact portion 11a, an intermediate supporting portion 12a obliquely connected between the flat top contact portion 11a and the flat bottom soldering portion 15a, an upper turn R1a connected between the flat top contact portion 11a and the intermediate supporting portion 12a, a second turn R2a connected between the intermediate supporting portion 12a and the flat bottom soldering portion 15a, and two slots 13a respectively formed in the first turn R1a and the second turn R2a. This structure of spring plate 10a is still not satisfactory in function. Because the spring plate 10a has a substantially S-shaped profile, it may hook other objects during its installation in the motherboard 30a, thereby causing a deformation. Because a stress is produced during the formation of the first turn R1a and the second turn R2a, the flat top contact portion 11a and the first turn R1a are forced downwards at different extents upon loading of the shielding cover plate 40a, thereby causing the shielding cover plate 40a unable to be stably supported on the flat top contact portion 11a. Unstable contact between the plate shield 40a and the flat top contact portion 11a affects the EMI protective effect of the shielding cover plate 40a. Further, the spring plate 10a may be deformed permanently when received a high pressure.
The present invention has been accomplished to provide an EMI protective spring plate, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide an EMI protective spring plate, which does not hook other objects during its installation. It is another object of the present invention to provide an EMI protective spring plate, which keeps the loaded EMI protective shielding cover plate stably in balance. It is still another object of the present invention to provide an EMI protective spring plate, which has a lower dead point design that prohibits the spring plate from being deformed excessively. To achieve these and other objects of the present invention, the EMI protective spring plate comprises a flat top contact portion, a flat bottom soldering portion, an oblique supporting portion diagonally connected between the flat top contact portion and the flat bottom soldering portion, a front sliding portion obliquely downwardly extended from one end of the flat top contact portion toward the flat bottom soldering portion and inserted through a lower slot in the oblique supporting portion, and a rear sliding portion obliquely upwardly extended from one end of the flat bottom soldering portion toward the flat top contact portion and inserted through an upper slot in the oblique supporting portion.